Apparatus for stripping metal layers from metallic supports

ABSTRACT

An apparatus for stripping or peeling metallic layers, especially electro deposited metal in the form of sheets, from sheet-like metallic supports, e.g. an electrodeposition cathode. The apparatus comprises a conveyor arrangement for advancing the sheets in an upright orientation to a tower in which blades are displacable to shed to electrodeposited layers from the cathode. A guard or masking member hinged to each cathode is swung aside by a moving device to reveal a setback lateral edge of the metal layers at the top of the cathode. A wedge arrangement is passed between the electrodeposited layer and the cathode horizontally to lift this edge to accommodate the peeling blades between the electrodeposited layer and the cathode.

Sept. 5, 1972 G. CASAGRANDE ErAL 3,689,396 APPARATUS FOR STRIPPING METAL LAYERS FROM METALLIC SUPPORTS Filed Nov 10, 1970 4 Sheets-Sheet 1 G. CASAGRANDE T. DE MICHELIS A DE ROSS! F. GNESOTTO ATTORNEY p 1972 G. CASAGRANDE ETAL 3,689,396

APPARATUS FOR STRIPPING METAL LAYERS FROM METALLIC SUPPORTS Filed Nov. 10, 1970 4 Sheets-Sheet I B 3 G F G. CASAGRANDE T. DE MICHELIS A. DE ROSSI F. GNESOTTO INVENTORS AT TO R N EY p 1972 G. CASAGRANDE ET AL 3,689,396 APPARATUS FOR STRIPPING METAL LAYERS FROM METALLIC SUPPORTS Filed Nov. 10, 1970 4 Sheets-Sheet 4 G. CASAGRANDE T. DE MICHELIS A. DE ROSSI F.GNESOTTO INVENTORS ATTORNEY US. Cl. 204198 9 Claims ABSTRACT OF THE DISCLOSURE An apparatus for stripping or peeling metallic layers, especially electrodeposited metal in the form of sheets, from sheet-like metallic supports, e.g. an electrodeposition cathode. The apparatus comprises a conveyor arrangement for advancing the sheets in an upright orientation to a tower in which blades are displaceable to shed to electrodeposited layers from the cathode. A guard or masking member hinged to each cathode is swung aside by a moving device to reveal a setback lateral edge of the metal layers at the top of the cathode. A wedge arrangement is passed between the electrodeposited layer and the cathode horizontally to lift this edge to accommodate the peeling blades between the electrodeposited layer and the cathode.

(1) FIELD OF THE INVENTION Our present invention relates to an apparatus for stripping or peeling metallic layers from sheet-like supports or substrates and, more particularly, to an apparatus for the peeling of electrodeposited layers from electrodeposition electrodes with a minimum of manual eifort. The invention is particularly directed to the peeling of metal layers, in the form of zinc sheets, from aluminum cathodes or the like of the type commonly used in the e'lectrowinning of (2) BACKGROUND OF THE INVENTION In many electrodepositing or electrowinning processes, sheet-like metallic substrates constitute electrodes which are immersed in a depositing bath and receive coatings of a metal to be recovered. While, in some cases, the deposit is not coherent and may be removed from the cathode simply by scraping, other systems give rise to coherent deposits which can be peeled from the cathode.

The method of peeling the electrodeposited metal from the cathode is particularly important in the recovery of zinc of high purity by electrodeposition and electrowinning. In such systems, the zinc deposit forms a sheet which adheres to the sheet-aluminum cathode, but which can be detached by inserting a wedge between the zinc layer and the aluminum cathode along an edge or at a corner to lift the zinc layer and enable it to be peeled ofi in the form of the zinc sheet mentioned earlier. For the most part, such peeling operations have been carried out by hand or with manually operated devices requiring strength and skill on the part of the operator. As a consequence, the production rate is low and the high labor costs inordinately increases the cost of the metal. It should be understood also that manual peeling operations are often characterized by United States Patent "Ice imprecision and problems such as the tearing of the zinc sheet. This may result in material loss or a diminution in the quality of the recovered product.

(3) OBJECTS OF THE INVENTION It is the principal object of the present invention to provide an improved apparatus for stripping coherent metal layers from sheet-like metallic substrates whereby the aforementioned disadvantages are obviated.

It is another object of our invention to provide an improved apparatus for the removal of electrodeposited metal layers from cathode sheets which operates at a high rate and with precision, which requires a minimum of manual labor, which yields a stripped product of high quality, and which is rapidly operating and highly reliable.

It is also an object of this invention to provide an improved apparatus for removing zinc layers, in the form of sheets, from aluminum cathodes in an automatic or semiautomatic manner with a minimum of manual handling of the aluminum cathodes or the zinc sheets and with a minimum of deterioration of the sheets and cathodes.

It is still another object of the instant invention to provide an apparatus for the automatic detachment of zinc layers in the form of sheets from aluminum cathodes of the type used in the electrorecovery of zinc.

(4) SUMMARY OF THE INVENTION These objects and others which will become apparent hereinafter are attained, in accordance with the present invention, through the provision of a peeling station to which a succession of electrodes are delivered, preferably in an upright condition each electrode comprising an aluminimum or like cathode and zinc or other electrodeposited metal layers adhering to the opposite surfaces of the cathode.

According to an important feature of this invention, each of the cathodes is provided along its upper edge with a hinged guard or masking member or guard piece overlying the respective surfaces and, preferably, straddling a lateral edge of the cathode and constituted of electrically insulated material so that electrodeposition of zinc or the like cannot occur on this guard piece. The guard piece is automatically deflected by a bifurcated moving member, the legs of which also straddle the cathode, to expose laterally an edge of the electrodeposited layer on either side of the cathode. Wedge means is provided along the lateral flank of the cathode carrying the guard piece so that horizontal displacement (lateral displacement) of the wedge members across the cathode, peels the upper edge of each layer away from the cathode. Advantageously, the wedge member has a pair of jaws which can be urged together and apart in a direction transverse to the plane of the cathode.

Once the upper edge of each layer has been deflected somewhat away from the cathode, a pair of blades are driven downwardly between each layer and the cathode while the latter is held in place.

In this manner, sheets of zinc are peeled from the broad surfaces of the cathode and may be collected at the base of the peeling station. From the peeling station, the stripped cathode can be removed by conveyor means and deposited at a collecting station from which a number of such stripped cathodes can be delivered simultaneously to the electro-recovery installation.

More particularly, the wedge means is self-centering upon the cathode, i.e., is free to move'in the horizontal direction of displacement of the cathode which, as noted, is oriented in a vertical plane. The wedge jaws or members of the wedge means, moreover, can be spread apart to form a gap with a width equal to, for example, several thicknesses of the cathode so that, when these wedge members are clamped against the oposite surfaces of the cathode, the entire wedge means may shift horizontally into lateral alignment with the cathode. Advantageously a pneumatic cylinder is provided for shifting the horizontally elongated wedge members across the Width of the cathode.

According to still another feature of the instant invention, the bifurcated moving member is constituted as a fork displaceable by a pneumatic cylinder parallel to the direction of displacement of the wedge means and is disposed thereabove. The guard piece then may have a portion on the upper side of its pivot lying in the path of this fork and engageable thereby to swing the guard piece out of the path of the wedge means. On the other side of the fulcrum of the guard piece, arms normally extend in the vertical direction and define the vertical height of the freed edge of the zinc sheet, these arms having a length at least equal to the vertical width of the Wedge members.

It has also been found to be advantageous to constitute the blades such that they extend horizontally over approximately two thirds of the horizontal width of the cathode and clear the fork and the guard piece mentioned earlier. These blades are preferably displacea'ble by a pneumatic cylinder mounted in a tower at the peeling station and can be provided with soft cutting edges adapted to preclude tearing of the cathode. These edges may be composed of bronze and preferably are inclined to the horizontal in the manner of a guillotine blade to facilitate insertion of the blade between the zinc sheet and the aluminum cathode. We also provide hinge means swingably mounting the blade to its vertical pneumatic cylinder, the hinge means defining a horizontal axis perpendicular to the direction of displacement of the cathode and enabling the cutting edges of the blades to be swung toward and away from the cathode while remaining parallel with the surfaces thereof.

() DESCRIPTION OF THE DRAWING The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a perspective view of an apparatus for peeling zinc sheets from aluminum cathodes in accordance with the present invention, some of the parts being illustrated diagrammatically and other parts being removed or omitted for clarity;

FIG. 1A is an elevational view illustrating the skid upon which the zinc sheets are collected;

FIG. 1B is a diagrammatic detail view showing one of the transfer mechanisms for the conveyor means of the present invention;

FIG. 1C is a view similar to FIG. 1B but illustratin another transfer device;

FIG. 2 is a perspective view of a cathode according to the present invention showing the guard piece and the bifurcated moving member which cooperates therewith;

FIG. 2A is an elevational view corresponding to FIG. 2 but showing the part thereof in another operative position;

FIG. 3 is a perspective exploded View partly in diagrammatic form, illustrating the blade arrangement and the mounting means therefor;

FIG. 3A is an elevational view illustrating other features of the peeling blades;

FIG. 3B is a lateral cross section, further illustrating aspects of the mounting of the blades;

FIG. 4 is a perspective view of the peeling stage just prior to engagement of' theedge of the assembly by the wedge means; and

FIG. 5 is a sequence diagram showing a series of five stages in the operation of the wedge means.

(6) SPECIFIC DESCRIPTION 6(a) Structure In FIG. 1, we have shown a general view of the appara tus of the present invention which comprises a pair of parallel chain conveyors 1 designed to advance the aluminum cathodes 3 coated. zinc. layers 4, in the direction of the stripping station, i.e. in the direction of arrow A. The conveyors which are provided with sprockets 1a and are mounted on a frame 1b, the latter defining a channel 10 through which the electrodes can be fed without obstruction to the stripping station. A pneumatic motor 2 (or another fluid-responsive drive means) has an output sprocket 2a connected by a chain l d with the feed chains 1.

The electrodes 3, 4 are lowered by a crane or a fork lift vehicle, in batches upon the feed station constituted by a conveyor 1, etc., and are transported in the direction of arrow A as indicated earlier. To suspend the electrodes, each of them'is provided with"a"rigid*cross beam 5, provided withhooks 6, only some of whichare shown in FIG. 1. It will be apparent that each of the cathodes is equipped with such hooks which serve to suspend the electrodesfrom a conveyor whereby the electrodes may be delivered toha storage station preparatory to return to the electrodeposition installation.

Downstream of the feed conveyors 1 and extending through the peeling station, there are provided chain conveyors 7, the chains 7a of which have upper horizontal stretches substantially aligned with the corresponding runs of the feed chainsl. The chains 7a pass about sprocket wheels 71) and are driven by a pneumatic motor 8 (or other fluid-responsive means). i

All of the devices which operate in sequence and conjunction to remove the sheets of zinc from the aluminum cathode, are provided at the peeling station S and will be described in greater detail hereinafter. At the discharge endof the conveyor 7, we provide a transfermechanism 14 adapted to carry the individual stripped cathodes 3 from the conveyor 7 to a transport'device 15 in the form of a link belt conveyor having dependinghooks 15a and 15b engageable'with the hooks 6 of each of the stripped'cathodes. In other words, the stripped cathodes pass in the direction of arrow B onto the conveyor 15 and are carried bythe latter in the direction of arrow C hori zontally to a storage station T at which a further transfer device 16 shifts the stripped cathodes onto, a pair of conveyor chains 17 for movement in the direction of arrow D and retention until the crane or other transport arrangement isoperated to'colle'c't the" stackfo'f -cathodes and return them to the electrodeposition'tank. Theconveyor chains 17 have horizontal str'etches'located in line with the stretch 150 of conveyor 15'and pass over sprocket wheels 17a.' A pneumatic motor 18 (or other fluid-operated means) drives the chain 17'via chains 17b and may also be connected via'a belt'lsa with the transfer device 16. The conveyor chains 17 are mounted upon a frame 17c maintaining an open channel in the direction of arrow 1701.

Referring now to FIGS. 2,"-2Aand"3', itwill be apparent that each of the electrodes removed from the electrowinning bath comprises a rectangular aluminum plate"3,the* edges of "which are providedwith polyethylene tape strips 50 which strips arealso provided along 2 the bottom of the cathode arid serve to prevent electrodeposition'of zinc along the'edges'of the cathode to bridge the two 'zinc layers;

At the upper part of the aluminum"; cathode and along one edge thereof,' 'there is provided a guard piece or mask 10 of electrically insulating material, e.g. polyethylene or rubber. As seen in FIG. 2, the guard piece comprises a bifurcated element whose legs a and 10b straddle the aluminum plate 3 and are pivotally secured thereto by a pin 10c extending perpendicularly to the plate 3 and parallel to the direction of displacement thereof by the conveyor means 1 and 7.

The member 10 also comprises a channel-shaped body 10d, the channel of which is represented at 10c in FIG. 4 and in FIG. 2A and which accommodates the edge portion of the cathode 3 in the upper right-hand portion thereof, thereby masking the area 3a of this cathode to prevent electrodeposition of zinc thereon. The center of gravity of the guard piece 10 is located approximately at 10 and hence tends to swing the guard piece in the direction of arrow E (i.e. clockwise in FIG. 2) to hold the body 10d in masking position.

When the mask or guard piece is swung upwardly (FIG. 2A and FIG. 4), the well-defined edge 4a along the upper margin of each zinc layer is exposed and can be wedged free from the cathode.

At the peeling station S, moreover, we provide means for swinging the mask upwardly, i.e. in the counterclockwise sense, as shown in FIG. 2. This means includes a bifurcated member 19, the legs 19a and 19b of which straddle the cathode 3 and are aligned with the legs 10a and 10b of the guard piece 10 above the pivot 100. Hence, when the bifurcated member 19 is shifted to the left in an aligned position of the guard piece and this bifurcated member, the leading edge of the bifurcated member engages the upper portion of the guard piece and swings the masked body 10d upwardly until it assumes the position illustrated in FIG. 2A.

The bifurcated member 19 is displaceable by a pneumatic cylinder 9 mounted upon the support frame 13 of the peeling station S.

At the peeling station S, moreover, we provide a device for the detachment of the upper edges of the zinc sheets from cathode 3. This device comprises, as best seen in FIGS. 3 and 4, a pair of wedge members 30 adapted to flank the cathode 3 and shiftable in the direction of arrow F by a pneumatic cylinder 32a mounted upon the frame 13 which may be formed from steel bars or profiles welded together in a frame structure. The piston 32 of this cylinder is slidable within a guide 31 provided with a pair of cylinders 33, the pistons of which are shiftable in the direction of arrow G, i.e., prependicularly to the plane of the cathode 3.

The front edges of wedge member 30 are tapered in the direction of advance as shown in 30a and engaged beyond the freed edge 4a along the upper boundary of each sheet to pry the sheet loose from the cathode 3.

Also mounted on the tower frame 13 is a blade device generally represented at 12 and best seen in FIG. 3. The blade device comprises a pair of blades 12a and 12b engageable with opposite surfaces of the cathode 3 and vertically displaceable by pneumatic pistons 22 in the direction of I to shed the zinc sheets from the cathode as shown in FIG. 3. The lower edge 120 of each plate 12a, 12b is inclined to the horizontal H as best seen in FIG. 3A and is composed of a relatively soft material such as bronze to avoid marring the aluminum cathode. Furthermore, the blades are perforated at 12d to reduce their weight and have a width w which is approximately two thirds W, where W is the width of the electrode. Fins 20 converge downwardly (FIG. 3) to assist in wedging the zinc sheets 4 from the cathode 3. The inclined character of the chisel-shaped lower edge 120 of the plates 12a and 12b ensures a gradual introduction of the blades between the zinc plates and the cathode. The edges are otherwise parallel to the surfaces of the cathode. The blades 12a and 12b are hinged at 122 (FIG 3B) to the piston rod 21 of cylinders 22 for swinging movement about a horizontal axis parallel to the line H and thus can be moved by pneumatic piston-cylinder assemblies 24 toward and away from the cathode as shown in dot-dash lines in FIG. 3b. To this end, the cylinder 24 is mounted on a bracket 6 24a of the piston rod 21 and has a piston 24b which is articulated at 24c to an arm 24d alfixed to the plate 12a or 12b.

At their upper ends, the cylinders 22 are supported by bearing plate 23 (FIGS. 1 and 3) which carries two additional piston-and-cylinder assemblies 25, the pistons of which are connected with one another by cross-member 26, constituting part of the tower frame 13. The assemblies 25 serve to advance the blades 12a and 12b toward the upper edge of the zinc sheets and to withdraw the plate assembly 12 to clear the bar 5 and permit displacement of the stripped cathode. The blades are connected with one another by a pair of aligning quadrilaterals, each formed by a pair of vertical rods 27 interconnected by the respective blades 12a and 12b, and rigidly joined at the top by a cross bar 28, the rods 27 sliding in guide sleeves 29 supported by the tower frame 13.

The wedge members 30 are self-centering in the horizontal direction parallel to the direction of movement of the cathodes, i.e. in the direction of arrow K, for which purpose the wedges 30 may slide in a support 11 on rails not shown in the drawings. It will be apparent that, upon closure of the wedge members 30 via piston-and-cylinder arrangement 33, the wedge members engage the opposite faces of the cathode 3 and center themselves on the latter.

Below the tower 13, there is provided a skid 60 upon which the zinc sheets are deposited.

6 (b) Operation A cathode 3, deposited from above on conveyor 1, is advanced incrementally (step by step) to the right in the direction of arrow A in FIG. 1 until it passes over onto the conveyor 7 at the discharge end of the conveyor 1. The conveyor 7 may be continuously moving and may operate at a faster rate than conveyor 1 to rapidly deliver the cathode 3 to the stripping or peeling station S beneath the tower 13. A clamp may be provided to engage the cathode and hold it in position for further operations, or the conveyor 7 may be stopped. When the clamp is used, it is pneumatically operated under the control of the program which sequentially operates the various pneumatic devices via, for example, cam-controlled switches and electromagnetic valves. The programmer is represented generally at P. The fork 19 itself may constitute the clamping arrangement and is advanced in the direction of arrow L (FIG. 2) to engage the upper end of the mask 10 and swing the latter about its pivot in the counterclockwise sense, i.e., opposite the arrow E.

As shown in FIG. 2A, the mask 10 is rotated by member 19 to clear the uncovered zone 3a of the aluminum cathode. The member 19 may remain in place during the remainder of the stripping operation and is withdrawn only when the cathode is to be released.

The wedge members 30 are then shifted to the left (arrow F) in FIGS. 3 and 3A. In an operating step which will be described in greater detail with reference to FIG. 5, to gradually wedge the upper portion of each sheet 4 away from the aluminum cathode 3. Outwardly bent flaps of the zinc sheets are thus provided, as is illustrated in broken lines in FIG. 4.

The blade arrangement 12 is then lowered by means of pistons 25 and placed astride the cathode 3 whereupon the cylinders 24 are energized to swing the bottom edges of the blades 12a and 12b inwardly toward the aluminum sheet of the cathode 3 (dot-dash lines in FIG. 3b). The blade assembly can then be loaded further by cylinders 22. We prefer, however, to position the blades 12a and 12b prior to advance of the Wedge 30.

Wedges 30 are shifted in the direction of arrow F (FIG. 4) until the members 30 flank both sides of the uncovered zone 3a (note the transition from the starting position zero in FIG. 5 to the position 1 of this figure). The transverse cylinder arrangement 33 then close the members 30 against the aluminum cathode (position 2 in FIG. to center the assembly as previously described. Further advance of the members 30 by piston-and-cylinder arrangement 32, 32a gradually urges the wedges 30 between the upper portion of each zinc sheet 4 and the faces of cathode 3 (position 3 of FIG. 5). Piston 32 continues its advance while cylinder arrangements 33 shift the members 30' outwardly (position 4 of FIG. 5) to further increase the outward bend of the zinc sheet 4 and spread the sheets outwardly. Upon complete formation of the flaps at the upper edges of the sheets, members 30 are withdrawn (position 5 in FIG. 5).

The cylinders 22 then lower the blades 12a and 12b to further spread the sheets and cause them to be stripped from the cathode 3 and fall upon the skid 60. Advantageously, the cylinders 24 are controlled to maintain a slight clearance between the edges 12c and the aluminum faces of the cathode to prevent damage to the latter.

Once the stripping operation is concluded, fork 19 (FIG. 2) is withdrawn and permits the masking member to drop into its normal position as shown in this figure. The stripped cathode 3 is rapidly displaced by the conveyor 7 to its discharge end where it is engaged by the levers 14a of the pneumatically controlled transfer device 14. The hooks 6 are lifted onto the hangers 15a and 15b of the link-belt conveyer 15 which runs parallel to the broad surfaces of the cathode and permits the operator to inspect the surface of the cathode for any adherent zinc. During the movement of the cathode of this conveyer, the polyethylene strips can be replaced or repositioned as necessary. At the end of conveyor 15, the other transfer device 16 whose levers 16a are cam-operated synchronously with the conveyer 17, transfers the cathode onto the conveyer 17. A stop may be provided at 172 to permit the cathodes to accumulate upon the conveyer 17.

All of the operations described above are carried out with pneumatic controls and pneumatic limit switches may be used to regulate the travel of the various members. The programmer P is representative of all such devices as well as the sequencing arrangement. Since each step is effected only after the previous one has been com pleted, synchronization is simplified and no phase displacement in the various operations occurs.

The main drive may be operated by push-button control although the automatic sequencing is preferred. All of the pneumatically displaceable assemblies may have counterpressure braking means with elastic suspension in the conventional manner (see Fluid Power, pages 193 fl'l, U.S. Government Printing Office, 1966). The parts of the machine subject to wear or breakdown are rapidly displaceable by the operator.

The apparatus described above has been used with a ten-second operating cycle to process 360 cathodes/hour with a zinc weight of 15 kg./cathode. 5.2 tons of zinc sheet are stripped per hour.

We claim:

1. An apparatus for recovering electrodeposited metal in the form of a metal layer, comprising:

a cathode sheet having at least one surface adapted to receive an electrodeposited metal layer;

means for supporting said sheet and the layer thereon in an upright position for removal of said layer;

a movable guard piece overlying said surface along a lateral edge of said sheet proximal to the top thereof for masking a zone of said surface and preventing deposition of metal thereon;

means for displacing said guard piece away from said zone to expose the same;

a wedge shiftable relatively to said sheet in line with said zone for peeling an upper edge of said layer away from said surface; and

a blade shiftable relatively with respect to said sheet in a direction transverse to the direction of relative movement of said wedge and said sheet and receivable between the peeled upper edge of said layer and said surface for deflecting said layer away from said surface.

2. An apparatus for the stripping of a layer from a cathode sheet for the electrodeposition of a metal thereon and adapted to receive metal layers on opposite surfaces, said apparatus comprising:

conveyor means for advancing said sheet in an upright position to a stripping stage;

Wedge means including a pair of wedge members flanking said sheet along the upper edges of said layers and shiftable across the surfaces of said sheet in a direction transverse to the direction of advance thereof for deflecting portions of said layers away from said cathode sheet along said upper edges;

blade means including a pair of blades flanking said sheet and each displaceable between a respective layer and said sheet while extending over a major fraction of the lengths of said edges and being shiftable transversely thereto between the deflected portions of said layers and said cathode sheet to peel said layers therefrom;

a guard piece straddling said cathode sheet along a lateral edge thereof in the region of the top of said layers and swingably mounted on said sheet for movement from a normal position in which said guard piece masks respective surface zones of said cathode sheet against deposition of said metal into a position in which said zones are exposed to define the portion of said layers engageable by said wedge members; and

means at said station for swinging said guard piece out of said normal position.

3. The apparatus defined in claim 2 wherein the lastmentioned means is a fork shiftable horizontally parallel to the direction of displacement of said wedge members and engageable with said guard piece.

4. The apparatus defined in claim 3, further comprising first fluid-responsive means actuatable to displace said wedge members relatively in a direction perpendicular to said cathode sheet, by a selfcentering motion on the latter.

5. The apparatus defined in claim 4 wherein said blade means further comprises second fluid-responsive means for shifting said blades along the faces of said cathode sheet, said blades being hingedly connected to said second fluidresponsive means for displacement of lower edges of the blades toward and away from the surfaces of said cathode, sheet third fluid-responsive means connected with each of said blades and energizable to swing said blade relative to said second fluid-responsive means.

6. The apparatus defined in claim 5 wherein said station is formed with a support structure, each of said blades being provided with an aligning quadrilateral having a pair of vertically extending rods, guide sleeves on said support structure receiving said rods, and connecting means joining said rods together.

7. The apparatus defined in claim 5 wherein said blades span approximately two thirds of the horizontal width of the respective surfaces of said cathode sheet, are provided with weight-reducing perforations, and are formed with fins facilitating outward deflection of said layers, the lower edges of said blades being composed of bronze and said cathode sheet being composed of aluminum.

8. The apparatus defined in claim 5 wherein said conveyor means includes a pneumatically operated first conveyor means for displacing a succession of such cathode sheets along a transport path, a second, pneumatically operated conveyor means receiving said cathode sheets from said first conveyor means and transferring them to said station and carrying stripped cathode sheets out of said station, a pneumatically operated transfer device for removing said stripped cathode sheets from said second conveyor means, a third conveyor means receiving said 10 stripped cathode sheets from said transfer device, a pneu- References Cited matically operated storage conveyor and a further trans- UNITED STATES PATENTS fer device synchronized with said storage conveyor for transferring said stripped cathode sheets from said third 3,501,385 3/1970 Jasberg conve or means to said storage conveyor. 5

9. 'i he apparatus defined in claim 8, further compris- HOWARD WILLIAMS Primary Exammer ing pneumatic control means for all of said fluid-respon- W. I. SOLOMON, Assistant m ner sive means, said pneumatically operated means and said pneumatically operated device for synchronously operat- CL ing same. 10 156-584; 204-12, 226, 281, DIG 7 

